This invention relates to analog display type electronic timepieces equipped with an alarm function, and more particularly to an analog display type electronic timepiece having an alarm system which is completely independent of the analog display system and functions electronically.
In an electronic timepiece having an analog type of time display, the hours and minutes of the current time are displayed by the positions of an hours hand and a minutes hand which are driven through a gear train by a motor, the motor being of a synchronous type such as a stepping motor and driven by a signal of fixed frequency, generally derived from a quartz crystal oscillator circuit by frequency division. There have been various methods proposed for equipping such a timepiece with an alarm function, whereby an audible and/or visible alarm signal is generated at some time designated by the timepiece user. These proposals generally however involve some mechanical or electro-mechanical coupling to the analog type time display system, and are complex and difficult to implement.
With the method of the present invention, an alarm system is provided for an analog type electronic timepiece which is completely independent of the analog time display system. To have an alarm signal generated at some desired point of time in the future, the timepiece user simply sets into an alarm time memory circuit the time difference between the current time and the desired alarm time point. This setting is performed by actuating a switch. Other than this switch, and an alarm buzzer if required, no other mechanical components are required so that the system of the present invention can easily be added to an existing design of analog type electronic timepiece. Some type of optical display means can also be incorporated, however, to indicate the face that the timepiece is in the alarm time setting mode of operation, although it is also possible to use the alarm buzzer for this purpose. In addition, a duel-function switch can be incorporated, so that the hours and minutes of the alarm time can be set independently.
It is therefore an object of the present invention to provide an improved type of electronic timepiece of analog display type equipped with an alarm function.
More particularly, it is an object of the present invention to provide an improved type of electronic timepiece of analog display type equipped with an alarm system which is independent of the analog display system of said timepiece.